The Curator and Responsible NASA Official are genuinely interested in answering your questions and helping you get the information you need. However, due to the large amount of e-mail they receive daily from the public, it is difficult to respond in a timely manner. In order to reduce the amount of time it takes to answer your questions, we ask you to browse the Frequently Asked Questions listed below to see if there is an immediate answer to your question. If your questions are not found there, please:

1. Check the Ask the Expert archives and the other NASA Frequently Asked Questions links, listed to the right.
2. If you cannot find your answer there, please send an e-mail to the Curator or Responsible NASA Official using the links to the right.

NASA's Jet Propulsion Laboratory in Pasadena, California, is responsible for
planetary probes and maintains much of NASA's solar system information. The phone number is 818-354-5011. The JPL Web site is at http://www.jpl.nasa.gov.

How do I get information on NASA satellites?

Goddard Space Flight Center in Greenbelt, Maryland, is the NASA Center responsible for satellite programs. It has information on satellite images, the Hubble Space Telescope, space tracking and space debris. The phone number is 301-286-5566. The GSFC Web site is at http://www.gsfc.nasa.gov/.

How does NASA receive and distribute my tax dollars?

Less than 1 percent of the federal budget goes to NASA. The budget for NASA is administered at NASA Headquarters in Washington, D.C. Inquiries on this subject should be directed to 202-358-1753. The main NASA Web site is at http://www.nasa.gov/.

Where do I find more technical information on NASA's
research?

Requests for NASA technical publications and papers should be directed to NASA's Center for Aerospace Information (CASI) at 301-621-0390. CASI's Web site is at http://www.sti.nasa.gov/.

Where can I get NASA souvenirs such as pens, caps, patches and stickers?

NASA does not recommend specific institutions or courses of instruction. Please contact accredited universities of your choice to determine if instruction is offered in the aerospace field. The qualifications for becoming an astronaut are covered in the Astronaut Selection and Training Brochure on the Web.

Can I see the shuttle and space station from the ground?

Yes, depending on your location, the orbit of the shuttle and station and lighting conditions, you might be able to see the shuttle and station from the ground. A detailed list of sighting opportunities is posted on the Web at: http://spaceflight.nasa.gov/realdata/sightings/index.html

I have a computer software program for tracking the shuttle and station, but it asks me for orbital elements or Keplerian elements. Where can I find these?

It is a very exciting, noisy, shaky ride for the first two minutes. Then the solid rocket boosters drop off and it gets a lot smoother, but there still is a strong push on the back of the astronauts' seats from all the power in the three main engines. Those three main engines burn fuel at an incredible rate -- approximately 3,785 liters (1,000 gallons) every second. The shuttle goes from standing still on the launch pad to more than 27,359 kilometers per hour (17,000 mph) in just over eight minutes. That means the astronauts go 3,219 kilometers per hour (2,000 mph) faster every minute.

Can NASA SkyWatch be used to determine if a satellite was visible in the past?

Yes. All you need to do to begin searching for a sighting in the past is to enter the time you want to begin searching in the "Threshold (GMT)" field on the Input Tab. This is true for past as well as future sightings. Remember, the format for the time is year/day:hour:min:sec in Greenwich Mean Time.

What causes the two sonic booms as the shuttle is approaching the landing site?

As the space shuttle re-enters the atmosphere at supersonic speeds, it creates shock waves that produce sonic booms. There is a shock wave at the orbiter's nose and one at the orbiter's tail as it re-enters These shock waves are created when the pressure disturbances caused by the shuttle flying through the air cannot escape the shuttle. These pressure waves travel at the speed of sound, but the shuttle is flying faster than the speed of sound, so a wave of pressure builds up along the nose and tail. As the shuttle altitude decreases, these pressure waves intersect the ground with a large pressure delta that your ears detect as a boom.

In fact, you'll hear not one, but two sonic booms! Because the space shuttle is so large, 37 meters (122 feet) long, you will hear the sonic booms created by both the nose and tail shock waves, which occur about one-half second apart. All supersonic airplanes produce two sonic booms, but because they happen so close to each other, you hear them as one sound.

The construction of the International Space Station began with the launch of the first element, the Russian Zarya Control Module, on Nov. 20, 1998. In accordance with our Vision for Space Exploration, completion of ISS is scheduled for 2010.

The first crew -- Commander Bill Shepherd, a U.S. astronaut; Soyuz Commander Yuri Gidzenko, a Russian cosmonaut, and Flight Engineer Sergei Krikalev, a Russian cosmonaut -- was launched on a Russian Soyuz spacecraft to begin permanent human habitation of the station in October 2000. From that point on, it has been permanently staffed. For more information, please see the Flight 2R Information page.

The International Space Station draws upon the resources and the scientific and technological expertise of 16 cooperating nations, including the United States, Canada, Japan, Russia and 11 participating member nations of the European Space Agency -- Belgium, Denmark, France, Germany, Italy, the Netherlands, Norway, Spain, Sweden, Switzerland and the United Kingdom. In addition, Brazil and Italy have signed on as payload participants.

Non-recyclable items are put on either a Russian Progress return vehicle, which will totally disintegrate re-entering Earth's atmosphere, or one of our shuttles, which brings it all the way back to Earth for disposal.

In 1988, President Ronald Reagan gave the station its original name -- Freedom. In the years that followed, Space Station Freedom's design underwent modifications with each annual budget cycle as Congress called for its cost to be reduced. In 1993, President Bill Clinton called for the station to be redesigned once again to reduce costs and include more international involvement. To stimulate innovation, teams from different NASA centers competed to develop three distinct station redesign options. The White House selected the option dubbed Alpha. After the Russians agreed to supply major hardware elements, many originally intended for their Mir 2 space station program, the station became known as the International Space Station.

NASA images generally are not copyrighted. You may use NASA imagery, video and audio material for educational or informational purposes, including photo collections, textbooks, public exhibits and Internet Web pages. This general permission does not include the NASA insignia logo (the blue "meatball" insignia), the NASA logotype (the red "worm" logo) and the NASA seal. These images may not be used by persons who are not NASA employees or on products, including Web pages, that are not NASA sponsored. See Reproduction Guidelines for Use of NASA Images and Emblems for more information.

NASA's archives, which start with historical images of aircraft and run through the most recent images obtained from NASA spacecraft, contain millions of images. This large number of images, combined with the constant, worldwide interest in the collection, makes it financially prohibitive for the agency to provide members of the public with free copies of images on demand. NASA images may be purchased from several sources. See Obtaining Copies of NASA Images for a list of suppliers.

How can I become an astronaut?

Any adult man or woman in excellent physical condition who meets the basic qualifications can be selected to enter astronaut training. For mission specialists and pilot astronauts, the minimum requirements include a bachelor's degree in engineering, science or mathematics from an accredited institution. Three years of related experience must follow the degree, and an advanced degree is desirable. Pilot astronauts must have at least 1,000 hours of experience in jet aircraft, and they need better vision than mission specialists. Competition extremely keen, with an average of more than 4,000 applicants for about 20 openings every two years. Astronaut recruiting occurs periodically. For more information, write to the Astronaut Selection Office, NASA Johnson Space Center, Houston, TX 77058. See the Astronaut Selection and Training Web site for more information.